From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Joakim Zhang qiangqing.zhang@nxp.com
commit ec15e27cc8904605846a354bb1f808ea1432f853 upstream.
RX FIFO enable failed could happen when do system reboot stress test:
[ 0.303958] flexcan 5a8d0000.can: 5a8d0000.can supply xceiver not found, using dummy regulator [ 0.304281] flexcan 5a8d0000.can (unnamed net_device) (uninitialized): Could not enable RX FIFO, unsupported core [ 0.314640] flexcan 5a8d0000.can: registering netdev failed [ 0.320728] flexcan 5a8e0000.can: 5a8e0000.can supply xceiver not found, using dummy regulator [ 0.320991] flexcan 5a8e0000.can (unnamed net_device) (uninitialized): Could not enable RX FIFO, unsupported core [ 0.331360] flexcan 5a8e0000.can: registering netdev failed [ 0.337444] flexcan 5a8f0000.can: 5a8f0000.can supply xceiver not found, using dummy regulator [ 0.337716] flexcan 5a8f0000.can (unnamed net_device) (uninitialized): Could not enable RX FIFO, unsupported core [ 0.348117] flexcan 5a8f0000.can: registering netdev failed
RX FIFO should be enabled after the FRZ/HALT are valid. But the current code enable RX FIFO and FRZ/HALT at the same time.
Fixes: e955cead03117 ("CAN: Add Flexcan CAN controller driver") Link: https://lore.kernel.org/r/20210218110037.16591-3-qiangqing.zhang@nxp.com Signed-off-by: Joakim Zhang qiangqing.zhang@nxp.com Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/can/flexcan.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
--- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -1252,10 +1252,14 @@ static int register_flexcandev(struct ne if (err) goto out_chip_disable;
- /* set freeze, halt and activate FIFO, restrict register access */ + /* set freeze, halt */ + err = flexcan_chip_freeze(priv); + if (err) + goto out_chip_disable; + + /* activate FIFO, restrict register access */ reg = priv->read(®s->mcr); - reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | - FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV; + reg |= FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV; priv->write(reg, ®s->mcr);
/* Currently we only support newer versions of this core